摘要
为研究重组竹钢夹板螺栓连接节点耐火极限及失效机理,依据ISO 834标准火灾试验方法设计并制作了3组24个螺栓连接试件,以螺栓数量、端距、行距、厚径比(竹板厚度与螺栓直径之比),持荷比(施加荷载与极限荷载之比)以及防火保护为试验参数,对其进行抗火性能试验研究。结果表明:当试件的厚径比为5.0~5.7时,单螺栓和多螺栓连接的破坏形态表现为螺栓孔压溃、竹材撕裂但螺栓未弯曲,当试件的厚径比为8.0~10.0时,破坏形态表现为螺栓孔压溃、竹材撕裂且螺栓弯曲,但厚径比对单螺栓连接耐火极限的影响并不显著;随着螺栓数量、端距和行距的增加,螺栓连接的耐火极限逐渐提高;增加持荷比使得螺栓连接耐火极限降低,防火保护对螺栓连接的抗火性能提升显著。通过对不同形式螺栓连接内部温度分析,揭示了火灾下重组竹材炭化性能及螺栓连接中孔受力对温度场的影响规律。
To investigate the fire resistance endurance and failure mechanism of bolted steel-PSB-steel connections, a total of 24 specimens in 3 groups were tested under furnace temperatures following the fire test requirements of ISO 834 to analyze the effects of bolt number, bolt spacing, end distance, thickness to diameter ratio (refers to ratio of thickness of PSB member and diameter of bolts), load ratio (refers to ratio of applied load and ultimate load) and fire protection on fire resistance properties. The results show that the failure mode of single and multi-bolted connections with the thickness to diameter ratio of 5.0-5.7 is bolt hole elongation followed by PSB member splitting without macroscopic deformations of bolts. When the thickness to diameter ratio is in the range of 8.0-10.0, the bolts exhibit visible bending deformations accompany with bolt hole elongation followed by PSB member splitting. However, the effect of thickness to diameter ratio for single bolt connections on fire resistance is not distinct. As the bolt number, bolt spacing and end distance increase, the fire resistance gradually increases. While increasing the load ratio the fire resistance decreases. Fire protection also has a noteworthy positive effect on fire resistance. The charring property of PSB members and the influence of force on heat field in bolted steel-PSB-steel connections exposed to fire is revealed by analyzing the temperature distribution.
作者
崔兆彦
惠勃涛
徐明
陈忠范
CUI Zhaoyan;HUI Botao;XU Ming;CHEN Zhongfan(Key Laboratory of Concrete and Prestressed Concrete Structures of China Ministry of Education,Southeast University,Nanjing 210096,China;School of Civil Engineering,Southeast University,Nanjing 210096,China)
出处
《建筑结构学报》
EI
CAS
CSCD
北大核心
2019年第9期20-27,共8页
Journal of Building Structures
基金
国家“十三五”科技支撑计划(2017YFC0703503)
江苏省自然科学基金项目(BK20151406)
关键词
重组竹材
钢夹板螺栓连接
标准升温试验
耐火极限
破坏模式
parallel strand bamboo
bolted connections with steel plates
standard test
fire resistance
failure mode
